NAME

sys/ipc.h - XSI interprocess communication access structure

SYNOPSIS

#include<sys/ipc.h>

DESCRIPTION

The <sys/ipc.h> header is used by three mechanisms for XSI interprocess
communication (IPC): messages, semaphores, and shared memory. All use a
common structure type, ipc_perm, to pass information used in
determining permission to perform an IPC operation.
The ipc_perm structure shall contain the following members:
uid_tuid Owner’s user ID.
gid_tgid Owner’s group ID.
uid_tcuid Creator’s user ID.
gid_tcgid Creator’s group ID.
mode_tmode Read/write permission.
The uid_t, gid_t, mode_t, and key_t types shall be defined as described
in <sys/types.h> .
Definitions shall be provided for the following constants:
Mode bits:
IPC_CREAT
Create entry if key does not exist.
IPC_EXCL
Fail if key exists.
IPC_NOWAIT
Error if request must wait.
Keys:
IPC_PRIVATE
Private key.
Control commands:
IPC_RMID
Remove identifier.
IPC_SET
Set options.
IPC_STAT
Get options.
The following shall be declared as a function and may also be defined
as a macro. A function prototype shall be provided.
key_tftok(constchar*,int);Thefollowingsectionsareinformative.

APPLICATIONUSAGE

None.

RATIONALE

None.

FUTUREDIRECTIONS

None.

SEEALSO

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .